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Chen SH, Sung YF, Oyarzabal EA, Tan YM, Leonard J, Guo M, Li S, Wang Q, Chu CH, Chen SL, Lu RB, Hong JS. Physiological Concentration of Prostaglandin E 2 Exerts Anti-inflammatory Effects by Inhibiting Microglial Production of Superoxide Through a Novel Pathway. Mol Neurobiol 2018; 55:8001-8013. [PMID: 29492849 DOI: 10.1007/s12035-018-0965-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 02/16/2018] [Indexed: 01/21/2023]
Abstract
This study investigated the physiological regulation of brain immune homeostasis in rat primary neuron-glial cultures by sub-nanomolar concentrations of prostaglandin E2 (PGE2). We demonstrated that 0.01 to 10 nM PGE2 protected dopaminergic neurons against LPS-induced neurotoxicity through a reduction of microglial release of pro-inflammatory factors in a dose-dependent manner. Mechanistically, neuroprotective effects elicited by PGE2 were mediated by the inhibition of microglial NOX2, a major superoxide-producing enzyme. This conclusion was supported by (1) the close relationship between inhibition of superoxide and PGE2-induced neuroprotective effects; (2) the mediation of PGE2-induced reduction of superoxide and neuroprotection via direct inhibition of the catalytic subunit of NOX2, gp91phox, rather than through the inhibition of conventional prostaglandin E2 receptors; and (3) abolishment of the neuroprotective effect of PGE2 in NOX2-deficient cultures. In summary, this study revealed a potential physiological role of PGE2 in maintaining brain immune homeostasis and protecting neurons via an EP receptor-independent mechanism.
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Affiliation(s)
- Shih-Heng Chen
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, NIEHS/NIH, 111 T.W. Alexander Dr., Research Triangle Park, NC, 27709, USA.
| | - Yueh-Feng Sung
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, NIEHS/NIH, 111 T.W. Alexander Dr., Research Triangle Park, NC, 27709, USA.,Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Esteban A Oyarzabal
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, NIEHS/NIH, 111 T.W. Alexander Dr., Research Triangle Park, NC, 27709, USA
| | - Yu-Mei Tan
- U.S. Environmental Protection Agency, National Exposure Research Lab, Research Triangle Park, NC, USA
| | - Jeremy Leonard
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Mingri Guo
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, NIEHS/NIH, 111 T.W. Alexander Dr., Research Triangle Park, NC, 27709, USA.,Department of Laboratory Medicine, Tianjin Haihe Hospital/Haihe Clinical Institute of Tianjin Medical University, Tianjin, China
| | - Shuo Li
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, NIEHS/NIH, 111 T.W. Alexander Dr., Research Triangle Park, NC, 27709, USA.,Department of Respiratory, Tianjin Medical University General Hospital, Tianjin, China
| | - Qingshan Wang
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, NIEHS/NIH, 111 T.W. Alexander Dr., Research Triangle Park, NC, 27709, USA
| | - Chun-Hsien Chu
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, NIEHS/NIH, 111 T.W. Alexander Dr., Research Triangle Park, NC, 27709, USA
| | - Shiou-Lan Chen
- Department of Neurology, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ru-Band Lu
- Institute of Behavioral Medicine, College of Medicine & Hospital, National Cheng Kung University, Tainan, Taiwan.,Department of Psychiatry, National Cheng Kung University, Tainan, Taiwan
| | - Jau-Shyong Hong
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, NIEHS/NIH, 111 T.W. Alexander Dr., Research Triangle Park, NC, 27709, USA.
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Zhou H, Zhang F, Chen SH, Zhang D, Wilson B, Hong JS, Gao HM. Rotenone activates phagocyte NADPH oxidase by binding to its membrane subunit gp91phox. Free Radic Biol Med 2012; 52:303-13. [PMID: 22094225 PMCID: PMC3253173 DOI: 10.1016/j.freeradbiomed.2011.10.488] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 10/18/2011] [Accepted: 10/22/2011] [Indexed: 12/21/2022]
Abstract
Rotenone, a widely used pesticide, reproduces parkinsonism in rodents and associates with increased risk for Parkinson disease. We previously reported that rotenone increased superoxide production by stimulating the microglial phagocyte NADPH oxidase (PHOX). This study identified a novel mechanism by which rotenone activates PHOX. Ligand-binding assay revealed that rotenone directly bound to membrane gp91(phox), the catalytic subunit of PHOX; such binding was inhibited by diphenyleneiodonium, a PHOX inhibitor with a binding site on gp91(phox). Functional studies showed that both membrane and cytosolic subunits were required for rotenone-induced superoxide production in cell-free systems, intact phagocytes, and COS7 cells transfected with membrane subunits (gp91(phox)/p22(phox)) and cytosolic subunits (p67(phox) and p47(phox)). Rotenone-elicited extracellular superoxide release in p47(phox)-deficient macrophages suggested that rotenone enabled activation of PHOX through a p47(phox)-independent mechanism. Increased membrane translocation of p67(phox), elevated binding of p67(phox) to rotenone-treated membrane fractions, and coimmunoprecipitation of p67(phox) and gp91(phox) in rotenone-treated wild-type and p47(phox)-deficient macrophages indicated that p67(phox) played a critical role in rotenone-induced PHOX activation via its direct interaction with gp91(phox). Rac1, a Rho-like small GTPase, enhanced p67(phox)-gp91(phox) interaction; Rac1 inhibition decreased rotenone-elicited superoxide release. In conclusion, rotenone directly interacted with gp91(phox); such an interaction triggered membrane translocation of p67(phox), leading to PHOX activation and superoxide production.
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Affiliation(s)
- Hui Zhou
- Neuropharmacology Section, Laboratory of Toxicology & Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, 27709
| | - Feng Zhang
- Neuropharmacology Section, Laboratory of Toxicology & Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, 27709
| | - Shih-heng Chen
- Neuropharmacology Section, Laboratory of Toxicology & Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, 27709
| | - Dan Zhang
- Neuropharmacology Section, Laboratory of Toxicology & Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, 27709
| | - Belinda Wilson
- Neuropharmacology Section, Laboratory of Toxicology & Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, 27709
| | - Jau-shyong Hong
- Neuropharmacology Section, Laboratory of Toxicology & Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, 27709
| | - Hui-Ming Gao
- Neuropharmacology Section, Laboratory of Toxicology & Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, 27709
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Saftig P, Klumperman J. Lysosome biogenesis and lysosomal membrane proteins: trafficking meets function. Nat Rev Mol Cell Biol 2009; 10:623-35. [PMID: 19672277 DOI: 10.1038/nrm2745] [Citation(s) in RCA: 1161] [Impact Index Per Article: 77.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Lysosomes are the primary catabolic compartments of eukaryotic cells. They degrade extracellular material that has been internalized by endocytosis and intracellular components that have been sequestered by autophagy. In addition, specialized cells contain lysosome-related organelles that store and secrete proteins for cell-type-specific functions. The functioning of a healthy cell is dependent on the proper targeting of newly synthesized lysosomal proteins. Accumulating evidence suggests that there are multiple lysosomal delivery pathways that together allow the regulated and sequential deposition of lysosomal components. The importance of lysosomal trafficking pathways is emphasized by recent findings that reveal new roles for lysosomal membrane proteins in cellular physiology and in an increasing number of diseases that are characterized by defects in lysosome biogenesis.
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Affiliation(s)
- Paul Saftig
- Department of Biochemistry, Christian-Albrechts University, Kiel, Germany.
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Chatelut M, Leruth M, Harzer K, Dagan A, Marchesini S, Gatt S, Salvayre R, Courtoy P, Levade T. Natural ceramide is unable to escape the lysosome, in contrast to a fluorescent analogue. FEBS Lett 1998; 426:102-6. [PMID: 9598987 DOI: 10.1016/s0014-5793(98)00325-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Since the generation upon cell stimulation of the second messenger ceramide has been reported to occur in an endosomal/lysosomal compartment, we investigated whether ceramide formed in the lysosomes can escape this compartment. The metabolic fate of radiolabelled ceramide produced by intralysosomal hydrolysis of LDL-associated [ceramide-3H]sphingomyelin or [stearoyl-1-(14)C]sulfatide was examined in fibroblasts from control individuals and a patient with inborn lysosomal ceramidase deficiency (Farber disease). The behavior of this radioactive ceramide was compared to that of a fluorescent (lissamine-rhodaminyl) ceramide analogue deriving from sulfatide degradation. While in Farber cells the natural, radiolabelled ceramide remained completely undegraded and accumulated in the lysosomes, the fluorescent derivative was rapidly converted to sphingomyelin. These findings strongly suggest that, in contrast to fluorescent derivatives, endogenous long-chain ceramide is unable to exit from lysosomes, therefore making the lysosomal ceramide unlikely to be a biomodulatory molecule.
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Affiliation(s)
- M Chatelut
- INSERM Unit 466, Laboratoire de Biochimie, Maladies Métaboliques, Institut Louis Bugnard, C.H.U. Rangueil, Toulouse, France
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Jiang X, Hill WG, Pilewski JM, Weisz OA. Glycosylation differences between a cystic fibrosis and rescued airway cell line are not CFTR dependent. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 273:L913-20. [PMID: 9374717 DOI: 10.1152/ajplung.1997.273.5.l913] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Altered glycosylation of mucus and membrane glycoconjugates could explain reported differences in binding of bacterial pathogens to cystic fibrosis (CF) versus normal tissue. However, because bacteria can alter cell surface glycoconjugates, it is not possible to assess the role of cystic fibrosis transmembrane conductance regulators (CFTR) in glycosylation in these studies. To address this issue, we have developed quantitative lectin binding assays to compare cell surface glycosylation in well-matched immortalized CF cells and rescued cell lines. The CF airway bronchial epithelial cell line IB3-1 consistently bound more peanut agglutinin (PNA) than its clonal derivative S9, which stably expresses functional wild-type CFTR. Pretreatment with neuraminidase increased PNA binding and abolished the difference between the two cell lines. However, infection of the IB3-1 cells with a replication-deficient recombinant adenovirus encoding CFTR restored CFTR function but did not alter PNA binding to cells. In contrast, treatment with the weak base ammonium chloride increased PNA binding to both cell lines as expected. Our data show that even clonally related CF and rescued cells can exhibit significant differences in carbohydrate processing. Although the differences that we found are consistent with the proposed role for CFTR in modulating intraorganellar pH, our data strongly suggest that they are CFTR independent. These studies add a cautionary note to the interpretation of differences in glycosylation between CF and normal primary tissues and immortalized cells.
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Affiliation(s)
- X Jiang
- Renal-Electrolyte Division Laboratory of Epithelial Cell Biology, University of Pittsburgh, Pennsylvania 15213, USA
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Porpaczy Z, Tomasek JJ, Freeman DA. Internalized plasma membrane cholesterol passes through an endosome compartment that is distinct from the acid vesicle-lysosome compartment. Exp Cell Res 1997; 234:217-24. [PMID: 9260888 DOI: 10.1006/excr.1997.3612] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cholesterol from the plasma membrane of MA-10 Leydig tumor cells is internalized into the cell and either esterified or used as substrate for steroid hormone synthesis. In the present studies we show that chloroquine and sphinganine cause LDL cholesterol and cholesteryl esters to accumulate in the cells. A lysosome fraction contained the excess cholesterol and cholesteryl esters. Both inhibitors blocked the conversion of plasma membrane cholesterol into intracellular cholesteryl esters and caused dose-dependent inhibition of dibutyryl-cAMP-stimulated progesterone synthesis. Radiolabeled cholesterol applied to the plasma membrane of MA-10 cells accumulated in the lysosome fraction of chloroquine and sphinganine-treated cells. Evidence that these inhibitors did not require the Golgi was provided by experiments using brefeldin A. Experiments utilizing a fluorescent cholesterol analogue and a lysosomal marker indicated that cholesterol entered the cells in structures that were different than the acidic vesicle-lysosome compartment. Consistent with this observation was the observation that the peak fluorescence fractions of cells subjected to density gradient centrifugation was of lower density than the lysosome fraction.
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Affiliation(s)
- Z Porpaczy
- Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City 73190, USA
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Abstract
We observed that the structural organization of early endosomes was significantly modified after cell surface biotinylation followed by incubation in the presence of low concentrations of avidin. Under these conditions early endosomes increased in size to form structures which extended over several micrometers and which had an intra-luminal content with a characteristic electron-dense appearance. The modified early endosomes were not formed when either avidin or biotinylation was omitted, suggesting that they resulted from the cross-linking of internalized biotinylated proteins by avidin. Accumulation of a fluid-phase tracer was increased after the avidin-biotin treatment (145% after 45 min). Both recycling and transport to the late endosomes still occurred, albeit to a somewhat lower extent than in control cells. Quantitative electron microscopy showed that the volume of the endosomal compartment was increased approximately 1.5-fold but that the surface area of the compartment decreased relative to its volume after avidin-biotin treatment. Finally, overexpression of a rab5 mutant, which is known to inhibit early endosome fusion in vitro, prevented the formation of these structures in vivo and caused early endosome fragmentation. Altogether, our data suggest that early endosomes exhibit a high plasticity in vivo. Cross-linking appears to interfere with this dynamic process but does not arrest membrane traffic to/from early endosomes.
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Affiliation(s)
- R G Parton
- European Molecular Biology Laboratory, Heidelberg, Germany
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Beaumelle BD, Gibson A, Hopkins CR. Isolation and preliminary characterization of the major membrane boundaries of the endocytic pathway in lymphocytes. J Cell Biol 1990; 111:1811-23. [PMID: 2121741 PMCID: PMC2116323 DOI: 10.1083/jcb.111.5.1811] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Plasma membrane, coated pits, endosomes, and lysosomes were isolated from a mouse T lymphoma cell line using a density shift protocol in which these compartments were selectively loaded with gold conjugates. The plasma membrane was prepared after selective labeling for 1 h at 2 degrees C with gold-ricin and gave a yield of 40% according to enzymatic and antigenic markers. Endosomes were obtained by loading the cells for 2 h at 22 degrees C with gold complexed to an antimouse transferrin receptor mAb. Coated pits were isolated using a similar procedure, but after an incubation at 10 degrees C, which allowed deep invagination of the pits but prevented internalization. The yield (calculated using the recovery of [125I]transferrin) was 32% for endosomes and 10% for coated pits. Finally lysosomes were prepared by loading the cells for 18 h at 37 degrees C with gold low density lipoproteins (LDLs) followed by a 3-h chase at 37 degrees C with LDL alone. The final lysosome yield (based on the recovery of lysosomal enzymes) was 16%. Studies of the protein composition of these cellular compartments on two-dimensional gels showed that while some major proteins are present throughout the pathway, specific proteins can be identified in each of the isolated fractions. The greatest change in the pattern of protein constituents seen along the pathway was between endosomal and lysosomal preparations.
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Affiliation(s)
- B D Beaumelle
- Department of Biochemistry, Imperial College of Science, Technology, and Medicine, London, England
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Raub TJ, Koroly MJ, Roberts RM. Rapid endocytosis and recycling of wheat germ agglutinin binding sites on CHO cells: evidence for two compartments in a nondegradative pathway. J Cell Physiol 1990; 144:52-61. [PMID: 2365746 DOI: 10.1002/jcp.1041440108] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The internalization and recycling of CHO cell plasma membrane components have been quantified by using iodinated wheat germ agglutinin (WGA) as an adsorptive tracer. Most of these binding sites are thought to be composed of a subpopulation of plasma membrane proteins called high-molecular-weight acidic glycoproteins (HMWAG). Greater than 90% of the WGA bound on the cell surface can be removed by brief treatment with N-acetylglucosamine (GlcNAc). At 37 degrees C, endocytosis of WGA that had been allowed to bind to the surface at 4 degrees C is curvilinear with an initial rapid phase occurring with a t1/2 of 6-8 min. Within 20 min, accumulation has slowed gradually to steady-state with 65% of the cell-associated WGA located intracellularly or resistant to removal by GlcNAc. These portions are unaffected by increasing the extracellular concentration of WGA from 0.003 microM to 2.8 microM. By using pulse-chase experiments, the observed decrease in rate of endocytosis is shown to be due to return of the WGA-HMWAG complexes to the cell surface. More than 60% of the WGA that had been internalized is recycled within 30 min, with a mean t1/2 of 17 min. Recycling involved at least two intracellular populations where a significant fraction (less than 30%) of the WGA-HMWAG complexes are lost gradually from the rapidly recycling pool. Most of the WGA-HMWAG complexes that had internalized are not delivered to the lysosome. These results demonstrate the magnitude of rapid and continuous recycling of WGA binding sites between the cell surface and endosomes in fibroblasts.
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Affiliation(s)
- T J Raub
- Drug Delivery Systems Research, Upjohn Company, Kalamazoo, Michigan 49001
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Draye JP, Courtoy PJ, Quintart J, Baudhuin P. A quantitative model of traffic between plasma membrane and secondary lysosomes: evaluation of inflow, lateral diffusion, and degradation. J Cell Biol 1988; 107:2109-15. [PMID: 2848849 PMCID: PMC2115686 DOI: 10.1083/jcb.107.6.2109] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We present here a mathematical model that accounts for the various proportions of plasma membrane constituents occurring in the lysosomal membrane of rat fibroblasts (Draye, J.-P., J. Quintart, P. J. Courtoy, and P. Baudhuin. 1987. Eur. J. Biochem. 170: 395-403; Draye, J.-P., P. J. Courtoy, J. Quintart, and P. Baudhuin. 1987. Eur. J. Biochem. 170:405-411). It is based on contents of plasma membrane markers in purified lysosomal preparations, evaluations of their half-life in lysosomes and measurements of areas of lysosomal and plasma membranes by morphometry. In rat fibroblasts, structures labeled by a 2-h uptake of horseradish peroxidase followed by a 16-h chase (i.e., lysosomes) occupy 3% of the cellular volume and their total membrane area corresponds to 30% of the pericellular membrane area. Based on the latter values, the model predicts the rate of inflow and outflow of plasma membrane constituents into lysosomal membrane, provided their rate of degradation is known. Of the bulk of polypeptides iodinated at the cell surface, only 4% reach the lysosomes every hour, where the major part (integral of 83%) is degraded with a half-life in lysosomes of integral to 0.8 h. For specific plasma membrane constituents, this model can further account for differences in the association to the lysosomal membrane by variations in the rate either of lysosomal degradation, of inflow along the pathway from the pericellular membrane to the lysosomes, or of lateral diffusion.
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Affiliation(s)
- J P Draye
- Laboratoire de Chimie Physiologique, University of Louvain, Brussels, Belgium
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Draye JP, Courtoy PJ, Quintart J, Baudhuin P. Relations between plasma membrane and lysosomal membrane. 2. Quantitative evaluation of plasma membrane marker enzymes in the lysosomes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1987; 170:405-11. [PMID: 2826161 DOI: 10.1111/j.1432-1033.1987.tb13714.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We have quantified, in cultured rat fibroblasts, the association to the lysosomal membrane of two classical plasma membrane markers, 5'-nucleotidase and alkaline phosphodiesterase I. To isolate highly purified lysosomal preparations, lysosomes were loaded with horseradish peroxidase (2-h cell uptake, 16-h chase) and isolated by isopycnic centrifugation in linear Percoll gradients, followed by a 3,3'-diaminobenzidine-induced density shift in sucrose gradients. Purified lysosomal preparations contained up to 50% of N-acetyl-beta-glucosaminidase of the homogenate. This lysosomal enzyme was enriched 33-fold in the most purified preparations. In the electron microscope, these preparations appeared to be highly purified and only contained organelles filled with diaminobenzidine reaction products. Analysis of purified preparations indicates that 0.5-0.8% of 5'-nucleotidase, but as much as 10.9-14.3% of alkaline phosphodiesterase I activities of the homogenate, are associated with lysosomes. After freezing-thawing, these activities remained essentially membrane-associated. The larger value obtained for alkaline phosphodiesterase I could not be ascribed to other lysosomal enzymes, as no such activity was detected at acidic pH. These two plasma membrane markers are thus unevenly distributed in the lysosomal compartment.
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Affiliation(s)
- J P Draye
- Laboratoire de Chimie Physiologique, University of Louvain, Brussels, Belgium
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